Mercury switch



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Application filed October 10, 1823. Serial No. 667,625.

a To'all whom it may concern: ."Be fit known that I ROY D. Manner, a citizen of the United tates, and resident of 'EastQOIange, county of'Esse'x, State of New flljJerseyfhave invented certain'n'ew and usefullinprovements in Mercury Switches,-o f fiwhic'hth efollowing is a specification.

invention relates to switches ofthe' h ch mercury is used to make and nn'ectlon between: electrical conduc- Up .ipresent considerable trouble has -bcen-expe'rienced withqswitches having con-' tainersoff-glass of high coeflicient'of expan- 1 l fl-sion'and-low-melting oint due to the break- -ing of the lass of t e container either at the point o rupture of the electrical connection or at or near the seal-in due to elecff-trical' conditions within the switch.

,2 This-trouble is particularly heavyin such "switches when they are used in inductive circuits due to the high voltage are induced fl at thebreakin of the circuit and the conselient-,-frapid c anges of temperatures produced within the switch tube. The change in temperature thus brought about is over an enormously wide range and occurs in an exceedingly short period of time and has an excessive destmctiye effect on glass or d in this type of'switch. The

comparatively rapid change again from the j high to thel'ow temperatures also has its de- 'teriorating; effect-upon the glass.

' a'consequence of these high temperaturcsf-and'jrapid temperature changes over widesranges glass in ordinary switches liyolfi s yp roded and eaten away with weakening of the glass and a L .jsetting up 6 Qexcessive strains'therein. The

I JQffZinductiVe .circuitsis likewise produced insu'ch switches in circuits. whiolt are 1 *Toobtailli ll; flewitch, that will lamps. The nitial, or cold,' resistance of the lamps used in such cases-is so much less than that of the lighted and hot lamps that when the circults to them is first'closed there is a. rush of hlgh current flow which is checked only by the increased resistance of the lamps wh1ch occurs when their temperature rises. The current fiowing during this rush is so high that m the aforesaid mercurytube type of swltch rapid temperature changes over a wide range occur with the same destruct1ve effect upon the glass of the switch that attends switches in inductive circuits as hercinbefore described.

As an example it is noted that in a stereopt-icon lamp circuit normally operating at 1,000 watts and 110 volts there is such a dif v ference between the hot and cold resistances dinarily made are quickly deteriorated and destroyed through the rapid and high temperature changes produced by it.

It is the purpose of this invention to rovide a switch of mercury tube type w ich will withstand and is substantially unaffected by rapid temperature changes over wide ranges.

It is further a purpose of this invention to provide. a switch of this type in which excessive temperatures are inhibited.

In the drawings Fig. 1 is a side view of a switch in which the glass used is G702P glass.

Fig.2 is a similar view of a switch of pyrex glass with G702P glass atthe seal-ins of the terminals, the latter indicated bycross sectioning. a

Fi 3 is a similar view of a switch of fuse [quartz with a graded glass seal-in as indicated by sectioning.

Fi 4 is a-detail view of a' seal-in in which the ifierentwg'lasses used are 7 indicated by different cross sectioning.

withstand cury tube switches above referred to asv orhigh voltage kicks ,as well as highcurrent Fig. 1 of the drawings shows an envelope surges with their consequent high tempera- 1 of boro-silicate glass containing an appretures I use for the switch tube glass that is ciable amount of lead and enerally known peculiarly adapted towithstand hi'gh temin the arts and trade as G702 glass. Formed peratures and rapid fluctuations in temperain the wall of said envelope are the wells 4 tures over wide ranges, ,and, when desired in combination with a gas in said tube such as hydrogen, which will assist in the dissipation of heat from the switch, the metal of the terminals being themselves tolerably I good conductors of heat.

In some of my switches I use a hero-silicate glass containing an appreciable amount of lead. This glass is generally known in the arts and in the trade as G702P glass, It has a thermal coefiicient of expansion near to that of tungsten which latter I use for the terminal seal-in of the switch. vThis glass I find has arc resisting qualities of a much higher order than ordinary glass used for th1s purpose. 1

For switches which are subjected to. much harder usage I use a boro-silicate glass containing an appreciable amount of aluminum extended periods'of time.

for the body of the switch tube, with the G702P glass at the seal-ins of the switch terminals. This glass is known generally in the arts and in the trade as pyrex or pyrex glass. It withstands heat and sudden temperature changes over wide ranges to a marked degree and I have found that in a switch of the mercury tube type that its combination with the mercury of the switch, the tungsten of the seal-in, and hydrogen gas with whichI fill my switches results in an object long desired in the switch art but not before obtained, namelya mercury tube switch which withstands the erosive action to which the inner surface of the switch is subjected during the making and breaking of the circuit through the switch as hereinbefore recite I r In the G702P glass switch as shown in Fig. l the combination of the glass, the mercury, thetungsten terminals and the hydroen gas with which I fill the switches results in a suflicient dissipationof the heat from current surges or voltage kicks and are to enable the switch to withstand such conditions up to extreme cases. The. pyrex switch combination results in a switch which. withstands even extreme cases ,of hard usage over Another switch I have invented is a com- -bination of mercury, hydrogen, tungsten terminals, fused quartz switch tube and a graded seal between the fused quartz an the seal-in of the terminals. This switch withstands extremely hard usage over extended periods of time and is used insplaces where the pyrex switch can not be used and in other.

laces to which it is peculiarly adapted. The i used quartz of the body of the tube withstands the most extreme hardships that switching conditions can impose on switches.

wells 4 and to span the space between them.

Before the envelope is sealedoff it is cleared of deleterious gases and filled with hydrogen.

.Fi 2 shows a switch tube of which the enve ope 5 is made of a boro-silicate glass containing an appreciable amount of aluminum and trade as pyrex lass. In this switch tube the wells 6 are ma e of the G702P glass above 'mentioned anddescribed. This form has the advantages of the pyrex glass with its resistance to the destructive erosive action of high temperatures, sudden changes of temperature over wide ranges, and the cuttin effect of high temperature arcs. The sea or fusion of the G7 02]? glass of the wells to the pyrex glass of the-envelope wall is made at a place removed from that at which disruption takes place between the main body of mercury and the. mercury of the wells atthe breaking-of the circuit through the switch, so as to flood the seal area with mercury at this moment, thus protecting the joints and other less resistant portions of the container walls.

Fig. 3 shows a switch tube with an englass at the bottom of the wells 8. Between the terminal seal-in there is a graded seal 9 of intermediate glasses as indicated in Figure 4. L

enerally known in the arts and- From what has been said above by way of illustration of my invention, it will be apparent to one skilled in the art that exhausted or gas filled switches may be made from quartz with graded glass seals running down to tungsten, or further down to platinum, or to the duplex metals known in the art as dumet, and the like; that the envelope 1 may be made of any glass having a coe'flicient of thermal expansion in the neighborhood of that of quartz, such as the ones men-- It is, of course, well-known that devices of this type are tilted or rotated-to make and break the connection between the pools 4, 4, in the making and breaking of a circuit through the switch.

I claim as my'invention:

1. In a mercury tube'switch, in combination, an envelope of bol'o-silicate glass car rying an appreciable quantity of'lead and contacts sealed into the walls of said envelope, said envelope being filled with a gas having the property of assisting in removinghea-t from-the high temperature points inthe envelope.

2. In a mercury tube "switch, in combination, an envelope of boro-silicate glass carrying an appreciable amount of lead and contacts sealed into the walls of said envelope, said envelope being filled with hydrogen.

. 3. In a mercury switch of the electrode pool typ boro-sillcate glass, carrying an appreciable (from the place of make an pools and the main body of mercury, and

amount of lead, wells communicatlng with the chamber formed by said envelope and sealed to the walls proper of said envelope, the sealing being made at a point remote (I reak of the tungsten electrodes sealed into said wells, said. envelope being filled with hydrogen.

4. In a mercury tube switch, in combination, an envelope of glass having a coefiicient of thermal expansion substantially that of b'oro-silicate g ass and greater than that of fused silica, contacts sealed into the walls of said envelope, and a contact making and breaking member in said envelope for bridging the gap between said contacts.

5. In a mercury tube switch, in combina tion, an envelope of glass having a 'coeflicient of thermal ex ansinn' substantially that of boro-silicate'gliiss and reater than that of fused silica,contacts sea ed into the walls'of said envelope, and a gas assisting in removing heat from said envelope.

6. In a-mercury switch, in combination, an envelope of glass having the property of withstanding high temperatures and rapid fluctuations in temperature and a well formed thereon of boro-silieate glass, mercury imsaid switch, and lead wires passing throu li tlie wall of the envelope and in contact with-said mercury.

7. In a mercury switch, in combination, an envelope of glass having the property of withstanding high temperatures and rapid fluctuations in temperature and wells formed thereon of boro-silicate glass, mercury in said switch, and lead wires passing through the wall of the envelope and in contact with said mercury.

8. In a mercury switch, in combination, an envelope of glass containing an appreciable quantity of metal and having the property of withstanding high temperatures e, in'combination, an envelope of able quantity of metal and having the property of withstanding high temperatures and rapid fluctuations in temperature, mercury pools in said envelope in the open position of said switch, and lead wires of tungsten like material passing through the wall of the cnvelope'and in contact with said pools. I

10. In a mercury switch, in combination, an envelope of bore-silicate glass carrying an i appreciable quantity of-metal, wells opening into said envelo e, and contacts sealed into the walls, of sai envelope and terminating inf'said wells.

'11. In a mercury switch, in combination, an envelope of boro-silicate glass 'carry'in an appreciable quantity of metal, a we opening into said.envelo'pe; and dividin the mercury into two pools 1n the open posltion of the switch, and contacts passing through the wall of the switch and terminating in said pools.

12. In a mercury switch, in combination; an envelope of boro-silicate glass carrying an appreciable quantity of metal, mercury pools in said switch, and tungsten lead in. wires sealed in the wall of the envelope and in contact with said. mercury pools.

13. In a mercury switch, in combination, an envelope of boro-silicate glasscarrying an appreclable quantity of metal,'mercury in said envelope in the open osition 0 said switch, and a gas in said envelope havin the roperty of assisting in the removal of ieat m tom the high temperature points in the en, velope 3 14. In a mercury switch, in combination,

an envelope of boro-silicate glass carrying "an appreclablequantity of metal, ,mercury 16. 'In a mercury switch, in combination, an envelope of boro-silicate glass, contacts sealed to said boro-silicate glass through a graded boro-silicate glass seal, and a quantity of mercury in said envelope.

17 In a mercury switch, in combination, an envelope of boro-silicate glass havin wells opening thereinto, contacts seale through the wall of said envelope and ter- 130 minating in said wells, and a body of mercury in said envelope.

18. In a mercury switch, in combination, an envelope of boro-silicate glass having Wells opening thereinto, contacts sealed through the wall of said envelope in said wells through a graded bore-silicate seal and terminating in said wells, and a body of mercury in said envelope.

19. In' a mercury switch, in combination, an envelope of lass having the property of withstanding high temperatures and rapid fluctuations in temperature, mercury pools in said envelope in the open circuit position of said switch and lead wires in contact with said-pools passing through the wall of the envelope in sealed relation to bore-silicate glass carried by said well.

20. In a mercury switch, in combination,

an envelope of lass having the property of 20 withstanding high temperatures and rapid fluctuation in temperature, mercury in said envelope, and lead wires passing through the Wall of the envelope in sealed relation to 7 glass carried by said envelope ROY D. MAILEY. 

